Automatic control for air-brake systems



L. J. ROOT. AUTOMATIC CONTROL FOR AIR BRAK'E SYSTEMS. v

APPLICATION FILED MAY,3. I918.

Patented Feb. 10,1920.

C] HOMI ma LEMMA J.

ROOT, O F CLARKSTO N, WASHINGTON.

AUTOMATIC CONTROL FOB AIR-BRAKE SYSTEMS,

Specification of Lettersfiatent.

Patented Feb. 10, 1920.

Application filed May 3, 1918. Serial No. 232,283.

To all whom it may concern:

Be it known that I LEMMA J. Roo'r, a citizen of the United States, residing at Glarkston, in the county of Asotin and State of WVashington, have invented certain new and useful Improvements in an Automatic Control for Air-Brake Systems, of which the following is a specification.

This invention relates to improvements in railway car brakes and it is the principal object of the invention to provide a novel form of pressure operated control means for the air-brake systems of railway cars, whereby to regulate the pressure applied to the car brakes in order that the same will be caused to properly function and as, a consequence, insure the stopping of a car provided therewith, hence rendering the same espec ally desirable for use in connection with trains composed of cars varylng in weight, whereby the braking pressure will be, applied in proportion to the weight and load of a particular car.

Another and equally important object of the invention is to provide a V capable of being regulated by the weight of the carload in order to insure the application of the brakes under pressure suificient to, elfectually stop the car provided there with. u

It is also .an object of this invention to provide a control means which can be automatically or manually regulated, as desired.

Other improvements and novel details in the construction and arrangement of the parts of the device. will be brought out more in detail in the description to follow, which,

for a clear understanding of the invention should be considered in connection with the accompanying drawings forming a part hereof and wherein is disclosed, for the purpose of illustration, a convenient and satisfactory embodiment of the invention.

I Figure 1 represents a longitudinal ver-' tical sectional view through the control device connected to a car body.

Figs. 2, 3 and 1, represent fragmentary longitudinal sectional views through the body showing the various positions of the relatively large piston.

Figs. 5 and 6 represen diagrammatical views showing variations in the arrangement of the fulcrum for the lever connecting the pistons, and

Fig. 7 represents a side elevation of a portion of a conventional type of air brake control means system illustrating the improved control device applied thereto.

Having more particular reference to the drawings, in connection with which like reference characters will designate corresponding parts, 1 represents a portion of a freight car provided with the improved control means and 2 a portion of one truck thereof. Arranged beneath the car body and supported upon suitable brackets, not shown, is the improved control means, the same including a body portion indicated in its entirety by the numeral 3 having a conduit & extending longitudinally therethrough. Cylinders 5 and 6 are arranged in the body portion and as will be noted, communicate with the conduit 4L by way of the upper ends thereof, the cylinder 6, which is of greater size than the cylinder 5, having one wall thereof arranged across the conduit 4 as indicated by the numeral 7. In this wall of the cylinder I form a port 8 whereby communication with the cylinder and the conduit can be established. It is to be also noted, thatthe, cylinder wall 7 is arranged in spaced relation from the adjacent end of the body portion 3, consequently providing a by-pass 8* for the end of the conduit in which the same is arranged, said by-pass being continued through the cylinder 6 and having an outlet in form of a port 9 formed in one side of said cylinder and communicating with the atmosphere.

Pistons 10 and 11 are slidable in the several cylinders 5 and 6 and as will be noted, are of sizes complemental thereto; the pistonll having a coiled spring 11 arranged outer end formed to PIOVlflQ a ratchet element 17, the purpose of which will be'pres ently apparent. To maintain the regulating rod 15 in adjusted position with respect to the body portion 3, when the same is adapted to be manually operated, a spring pawl portion and is engaged by a set-screw 19, the inner end of which has bearing on an adjacent portion of said body portion 8.

18 is secured to one end of the body 7 Thus, by turning the set-screw 19 in one direction the pawl 18 will be caused to ride upwardly thereon and as a consequence, disengaged from the ratchet element 17. However, by turning the screw in a reverse direction the pawl will be allowed to engage with the ratchet element 17, thereby serving to maintain the same in an adjusted position. If desired, one side of the ratchet element 17 may be provided with a plurality of graduations such as designated by the numeral 20 whereby an operator may accurately position or adjust the same to permit operation of the pistons 10 and 11 upon the presence of predetermined pressures in the brake cylinder. An expansible coil spring 21 is arranged in the body portion 3 about the regulating rod 15, one end of the same bearing on said body portion while the remaining end has bearing on the bracket 14. In this way, the regulating rod will normally tend to move inwardly.

To provide means whereby the control can be operated due to the weight of the carload, I secure to the under side of the car body a bracket plate 22, mounting brackets 23 and 24 thereon. Pivotally engaged with the bracket 23 is a slotted arm 25 having connection with an adjustable sectional rod 26 which extends downwardly into engagement with the car truck 2, while the outer end of said slotted arm receives an adjusting bolt 27 therein, which bolt is also passed through the slotted end of a bell crank lever 28, the remaining end of said lever being also slotted and adjustably engaged with a sectional adjustable bar 29 by means of a bolt 30. As will be noted, the outer end of the bar 29 is slotted and is capable of being adjustably connected to the adjacent end of the ratchet element 17 by means of a set-screw 31 or like fastening device. Since the bars 26 and 29 are adjustable, it will be understood that the same can be made various lengths to take up any play therebetween, while the connections 27 and 30 can be adjusted to increase or decrease the movement of the regulating rod 15 upon movement of the car body with relation to its truck. A stop lug 32 is arranged inthe lower portion of the cylinder 6 to limit the downward movement of the piston 11.

The terminal of the conduit or passage 4 adjacent the cylinder 5 is connected by a pipe 40 with the usual triple-valve 41 which has connection with the train pipe 42 and auxiliary reservoir 43. The opposite terminalv of the conduit 4 is connected by a pipe 44 with thebrake cylinder 45.

In operation, and assuming that the car is empty or carrying a comparatively light load, the fulcrum roller 13 is moved toward the piston 11 to the approximate position shown in Fig. 5, by the car body carried arm 25 and lever 28 having connection with the car truck 2 and roller 13, respectively, and consequently the mechanical advantage of the leve 12 is with the small piston lO. In normal position, that is with the air pressure reduced in the pipe 40 and conduit 4, the piston 11 is elevated, as shown in Fig. 4, and the air in the brake cylinder 45 and pipe 44 is permitted to escape through the ports 8 and 9 and the port 46 in the body 3 to the atmosphere. However, when air from the auxiliary reservoir 43 is admitted to the conduit 4 the pressure acting upon the large piston 11 depresses the latter, uncovering the port 8 and admitting air to the brake cylinder through the pipe 44 and applying the brakes with a force according to the pressure of the air. The air passing through the port 8 enters the chamber under the piston 11 through the port 8 and acting thereon, with the assistance of the piston 10 which, as stated, has a mechanical advantage over the piston 11 owing to the location of the lever fulcrum 13, moves the piston 11 to the intermediate position illustrated in Fig. 2 so as to close communication between the conduit 4 and brake cylinder before the pressure in the brake cylinder becomes equal to the pressure in the conduit 4. The pistons remain in this balanced position as long as the pressure in the conduit 4 remains constant but when the pressure is increased, the piston 11 is again dc pressed and air admitted to the brake cylinder until the pistons 10 and 11 are again balanced and the port 8 again closed. When the brakes are released by a reduction of pressure in the pipe 40 the air acting upon the bottom of the piston elevates the latter to the position shown in Fig. 4 and air. from the brake cylinder escapes through the ports 8 9 and 46.

When the car is carrying a comparatively heavy load, the fulcrum roller is moved toward the small pistonv 1O occupying the approximate position shown in Fig. 6, thus decreasing the mechanical advantage of the piston 10 over the piston 11. WVith the lever fulcrum so adjusted, a greater proportion of air pressure in the chamber 4 is admitted to the brake cylinder 45 before the pistons are balanced and the port 8 closed and so the braking force of the heavily laden car is increased over the lighter car.

I claim:

1. In combination with the brake cylinder and triple-valve of an air brake system, an automatic controlling device interposed between the valve and cylinder, said device including a hollow body, cylinders arranged in said body, fluid pressure operated pistons reciprocably mounted in said cylinders, a lever connecting said pistons, one of said cylinders having a permanently open port.

arranged under the piston and having diametrically opposed ports therein com,- municating with the atmosphere and with the brake cylinder and adapted to be alternately uncovered during reciprocation of the piston, said piston being arranged to cover both of the last mentioned ports in its intermediate position, and a movable fulcrum for the lever controlled by the weight of the car.

In combination with the brake cylinder, brake pipe and triple-valve of an air brake system, a hollow body interposed between the triple-valve and cylinder, cylinders arranged in the hollow member, a balance piston reciprocably mounted in one of the last named cylinders arranged to be acted upon by the fluid pressure in the hollow member, a piston valve reciprocably mounted in the other of the last named cylinders, the wall of the last named cylinder having a permanently open port oominunicating with the brake cylinder and arranged below the piston valve, said cylinder being provided with diametrically opposed ports adapted to be alternately uncovered during reciprocation of the valve, said piston valve being arranged to simultaneously cover both of the last named ports when in its intermediate position, a lever connecting the balance piston and the piston valve,

and a movable fulcrum fo said lever controlled by the weight of the car.

3. In an automatic control for air brake systems, a body having a longitudinal conduit therethrough for the passage of the fluid pressure operating the air brakes, a cylinder arranged in the body communicating with the conduit therein, a piston reciprocably mounted in the cylinder controlling the passage of fluid, a second cylinder arranged in the body, a balance piston arranged in the last named cylinder, a lever connecting the pistons, a movable fulcrum for the lever controlled by the Weight of the car, the first mentioned cylinder having a port therein admitting air below the first mentioned piston, said cylinder having the second port arranged above the first port and adapted to be uncovered when the piston is depressed as when the fluid pressure above the piston exceeds the fluid pressure below the piston, said cylinder having another port arranged intermediate the first mentioned ports adapted to be uncovered when the'piston is elevated to permit escape of fluid from the lower portion of the cylinder.

In testimony whereof, I affiX my signa ture hereto.

LEMMA J. ROOT. 

